. >> hey, there -- >> reporter: take ben stiller. he gets attention for his foundation, stiller strong, by producing hilarious videos. >> matt damon, he claims water -- >> how did he claim water? is he aqua man? >> reporter: consider this. damon talks about water on youtube, 4,000 hits. the video with sarah silverman -- ♪ who's that knocking at my door? ♪ >> reporter: viral. damon says his strong suit is getting people to care. >> because there's a lot of sort of low-hanging fruit, so to speak. there are so many people that we can help. >> do you see a solution in your lifetime? >> yes, we do. in fact, that's why we're here. >> reporter: water.org has helped 1 million people so far, but as damon says, there's still another 880 million people to go. nonetheless, he says it's a start and it's a good one. he believes that this whole idea of water credit, meaning, giving people affordable loans in places where getting clean water is a challenge is really working. and he says he believes it has the potential to reach up to 100 million